New, Close-Up View Probes the Nature of Sunspots

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Seriously, I don’t think we should stare at this too long … but for scientists who plan to, this new, high-resolution view of a sunspot stands to unlock secrets of the Sun’s mysterious energetics.

In the just-released image above, the interface between a sunspot’s umbra (dark center) and penumbra (lighter outer region) shows a complex structure with narrow, almost horizontal (lighter to white) filaments embedded in a background having a more vertical (darker to black) magnetic field. Farther out, extended patches of horizontal field dominate. For the first time, scientists have modeled this complex structure in a comprehensive 3D computer simulation, giving scientists their first glimpse below the visible surface.

The international team of scientists, led by the National Center for Atmospheric Research (NCAR) in Boulder, Colorado, say the high-resolution simulations of sunspot pairs open the way for researchers to learn more about the vast, mysterious dark patches on the Sun’s surface. Sunspots are the most striking surface manifestations of solar magnetism, and they are associated with massive ejections of charged plasma that can cause geomagnetic storms and disrupt communications and navigational systems. They also contribute to variations in overall solar output, which can affect weather on Earth and exert a subtle (and as-yet deciphered) influence on climate patterns.

The new research, by scientists at NCAR and the Max Planck Institute for Solar System Research (MPS) in Germany, appears this week in Science Express.

“This is the first time we have a model of an entire sunspot,” says lead author Matthias Rempel, a scientist at NCAR’s High Altitude Observatory. “If you want to understand all the drivers of Earth’s atmospheric system, you have to understand how sunspots emerge and evolve. Our simulations will advance research into the inner workings of the Sun as well as connections between solar output and Earth’s atmosphere.”

Ever since outward flows from the center of sunspots were discovered 100 years ago, scientists have worked toward explaining the complex structure of sunspots, whose number peaks and wanes during the 11-year solar cycle. Sunspots encompass intense magnetic activity that is associated with solar flares and massive ejections of plasma that can buffet Earth’s atmosphere. The resulting damage to power grids, satellites, and other sensitive technological systems takes an economic toll on a rising number of industries.

Creating such detailed simulations would not have been possible even as recently as a few years ago, before the latest generation of supercomputers and a growing array of instruments to observe the Sun. Partly because of such new technology, scientists have already made advances in solving the equations that describe the physics of solar processes.

Source: University Corporation for Atmospheric Research (UCAR), via American Astronomical Society (AAS) press wire